The present invention relates to an adjustable wrench and in particular to an adjustable wrench which is so constructed as to prevent or minimize a turning or twisting movement of the moveable jaw of the wrench during operation thereof and to maintain the close fit of the moveable jaw face and the stationary jaw face about a nut when the nut is being loosened or tightened.
There are many different types of adjustable wrenches found in the prior art. Those having a moveable or an adjustable jaw are constructed with threads which are utilized to move the adjustable jaw face towards or away from the stationary jaw face. The construction of these wrenches is such that when a force is applied to a nut to be turned, the force applies a turning moment or twisting moment to the moveable jaw member thus causing it to pivot away from the surface on which it rests about a point which tends to apply undue pressure to the threads or the pivot point thus causing the jaw to loosen and the threads to be damaged so that with continued use, the adjustment becomes more and more difficult to maintain. Thus, in each of the prior art wrenches, the forces applied during operational use of the wrench tend to force the moveable jaw away from the support surface on which it rides. It is this structural defect which creates the problems with the prior art adjustable wrenches.
The present invention overcomes the defect of the prior art adjustable wrenches by providing a support surface on which the moveable jaw member can rest and by so constructing the jaw member face of the moveable jaw that when the wrench is used the forces generated are applied to the moveable jaw face in such a direction as to force the moveable jaw member tightly against the support surface thereby removing undue stresses and strains from the moveable jaw member and tending to hold the moveable jaw member fixedly in place during use of the wrench. Thus, with the present inventive construction, it is impossible for the moveable jaw member to be separated even minutely from the support surface upon which it rests and moves and thus it is not subject to bending or twisting. Because of this unique construction, the wrench body has greater strength and stability and does not have to be made of such thick construction as do ordinary adjustable wrenches. Further, the wrench tends to stay tightly fit about a nut during use.
Also, no ratchet wrenches are known to applicant which utilize the above disclosed principle wherein the wrench, in the direction of applying force to the bolt or nut generates forces which are applied to the moveable jaw face in such a direction as to force it tightly against the support surface on which it rests thereby removing undue stresses and strains from the moveable jaw member but at the same time allowing the wrench to ratchet when it is turned in the opposite direction.